Surface coverings containing fused recycled material and processes of making the same

ABSTRACT

A backing or an intermediate layer for a surface covering is described which comprises a fused recycled material, wherein the material comprises a thermoplastic material, for instance, a vinyl material from a vinyl backed carpet or vinyl backed carpet manufacturing waste or both. Surface coverings containing the backing or intermediate layer of the present invention are also described as well as methods of making the backing or intermediate layer and methods of making the surface coverings containing the backing or intermediate layer of the present invention.

This application is a divisional of U.S. application Ser. No. 09/243,124filed Feb. 3, 1999, now U.S. Pat. No. 6,316,075, which is acontinuation-in-part of U.S. Provisional Application No. 60/073,718,filed Feb. 4, 1998, which is incorporated in its entirety by referenceherein.

BACKGROUND OF THE INVENTION

The present invention relates to backings for surface coverings, andmore particularly relates to backings which contain recycled material aswell as methods of making such products and incorporating them intosurface coverings.

At the present time, most of the post-consumer vinyl backed carpets andcarpet manufacturing waste go to landfills or are destroyed by othermeans such as burning. With the environment being of a global concern,the disposal of vinyl backed carpets and manufacturing waste which iscurrently done is not an acceptable option.

Further, recycling of vinyl backed carpets has been attempted but atmost, manufacturers have taken recycled material and reduced it toliquid plastisol form in order to form a carpet backing withconventional coating and curing processes. However, such a process haslimitations in that only very small amounts of recycled material can beincorporated into a plastisol mix, such as about 5% or less by weight,and because the oil absorption of recycled material is very high, highlevels of plasticizers in plastisols are needed which can lead tofurther problems. With high levels of plasticizers and plastisols,further processing by conventional methods can become difficult, if notimpossible.

Thus, there is a desire by manufacturers to develop ways to use recycledmaterial like carpet backing, such that large amounts of recycledmaterial can be incorporated into products.

SUMMARY OF THE PRESENT INVENTION

A feature of the present invention is to provide a material. e.g., asurface covering, that can contain up to 100% recycled material in oneor more components or layers.

Another feature of the present invention is to provide a backing for asurface covering containing recycled material.

An additional feature of the present invention is to provide a surfacecovering containing a backing or intermediate layer which uses up to100% recycled material.

A further feature of the present invention is to provide a method ofmaking a backing from recycled material and incorporating the backinginto surface coverings.

Additional features and advantages of the present invention will be setforth in part in the description which follows, and in part will beapparent from the description, or may be learned by the practice of thepresent invention. The objectives and other advantages of the presentinvention will be realized and attained by means of the elements andcombinations particularly pointed out in the written description andappended claims.

To achieve these and other advantages and in accordance with thepurposes of the present invention, as embodied and broadly describedherein, the present invention relates to a backing or an intermediatelayer for a surface covering which contains a fused recycled powder. Therecycled powder contains at least a thermoplastic material and thebacking or intermediate layer can optionally include other materials,including virgin thermoplastic materials.

The present invention further relates to a surface covering whichcontains the backing described above.

The present invention, in addition, relates to a method of making abacking or intermediate layer for a surface covering and includes thesteps of applying at least recycled powder to a substrate to form alayer, where the recycled powder contains at least one thermoplasticmaterial; and fusing the recycled powder to form a continuous backing orintermediate layer.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory onlyand are intended to provide a further explanation of the presentinvention, as claimed.

The accompanying drawings, which are incorporated in and constitute apart of this application, illustrate embodiments of the presentinvention and together with the descriptions serve to explain theprinciples of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a flow chart showing one embodiment of a method of the presentinvention.

FIG. 2 is a schematic drawing showing the various steps of making asurface covering which includes a backing containing recycled material.

FIGS. 3 a-e are cross-sectional views of surface coverings according toseveral embodiments of the present invention.

DETAILED DESCRIPTION OF THE PRESENT INVENTION

The present invention relates to a backing (also known as a backinglayer) and can be a secondary backing or an Intermediate backing layerfor a surface covering. In one embodiment, the backing layer orintermediate layer contains at least a fused recycled material. Therecycled material contains at least one thermoplastic material. Variouscoatings or layers are discussed herein, and unless stated otherwise,are preferably of a substantially uniform thickness and can be appliedusing techniques known to those skilled in the art.

For purposes of the present invention, a surface covering can be anysurface covering which makes use of a backing and/or intermediate layer,such as a floor covering, wall covering, ceiling covering, countertopcovering, and the like. Examples of floor coverings include, but are notlimited to, textile substrates, such as carpets, and resilient flooring,such as vinyl flooring or vinyl surface coverings. Particularlypreferred examples of textile substrates are hard backed and cushionbacked textile substrates. While the present invention will be describedwith respect to the preferred embodiment which is floor coverings, andin particular textile substrates and resilient flooring, the presentinvention can be applied to other types of surface coverings containingbacking and/or intermediate layers in view of the disclosure herein.

Preferably, the textile substrate is a broadloom carpet, modular tile,or a wide roll carpet (e.g. 6 ft. wide). Most preferably, the textilesubstrate is tile or 6 ft. roll goods.

The textile substrate comprises textile fibers defining a fibrous face,a primary backing to which the textile fibers are secured, and asecondary backing secured to the primary backing. For purposes of thepresent invention, the term “textile substrate” relates to, but is notlimited to, a fiber, web, yarn, thread, sliver, woven fabric, knittedfabric, non-woven fabric, upholstery fabric, tufted carpet, and piledcarpet formed, from natural and/or synthetic fibers.

The backing or backing layer for purposes of the present invention canbe any layer or substrate which has one or more additional layersadhered to a surface of the backing layer. Thus, the backing can be thelayer which is in contact with the sub-surface, such as a sub-floor, orcan be an intermediate layer with other layers above and below theintermediate backing layer.

The recycled material, preferably a powder, contains at least one typeof thermoplastic material. The recycled powder used in the presentinvention is preferably a powder obtained from post-consumer productswhich contain at least one thermoplastic material. Preferably, thepost-consumer product is a carpet and/or carpet manufacturing waste, andmore preferably is a vinyl backed carpet and/or vinyl backed carpetmanufacturing waste. Preferably, substantially no thermosetting materialis part of the recycled material (e.g. less than 5% by weight), and morepreferably no thermosetting material is present with the recycledmaterial.

With regards to the backing material, for purposes of the presentinvention, the backing is a thermoplastic material. The thermoplasticmaterial can be an aliphatic thermoplastic resin such as one derived bypolymerization or copolymerization of an ethylenically unsaturatedmonomer. The monomer can be a ethylenically unsaturated hydrocarbon suchas an olefin or a nitrile (such as an acrylonitrile), vinyl orvinylidene chloride, vinyl acetate, or an acrylate, such as,ethylacrylate or methylmethacrylate. More particularly, thethermoplastic material can he a polyethylene, ethylene/vinyl acetate,polyvinyl chloride, polyisobutylene, and the like. Preferably, thethermoplastic material is a vinyl-type material such as a vinyl resinand more particularly a polyvinyl chloride-type material.

Thermoplastic materials are not subject to chemical change when heated.Thermoplastic materials are not infusible, consequently they will gel orsoften when a solvent is applied. Suitable polymers for the backinglayers of the present invention are derived from at least one monomerselected from the group consisting of acrylic, vinyl, chlorinated vinyl,styrene, butadiene, ethylene, butene, and copolymers or blends thereof.A preferred coating composition is a polymer or copolymer of a vinylcompound, e.g., polyvinyl chloride, polyvinylidine chloride,polyethylene chloride, polyvinyl acetate, polyvinyl acetal, and thelike, and copolymers and mixtures thereof. A specific example of a resincoating composition is a vinyl chloride, resin-based plastisol, whereinthe plasticizer component of the plastisol is a phthalate-basedcompound, such as an alkyl phthalate substituted one or two times with alinear or branched C5-C12 alkyl group, which is included in an amount byweight equal to between about 15 to 60 percent of the weight of thevinyl chloride resin component. Particular vinyl chlorides includeVinycel 124 (Policyd SA DE CV, Mexico), Geon Registered ™ 13 oz (GeonCompany, Cleveland, Ohio), Pliovic—70 (The Goodyear Tire and RubberCompany, Akron, Ohio), and Oxy 67SF (Occidental Chemical Corp., Dallas,Tex.). Particular alkyl phthalate plasticizers include SanticizerRegistered ™ 160 (Monsanto Company, Saint Louis, Mo.), PalatinolRegistered ™ 711P (BASF Corporation, Parsippany, N.J.), and Jayflex DHP(Exxon Chemical America, Houston, Tex.).

The backing can be a cushion-back or a hard back backing. In moredetail, the backing can be a solid thermoplastic backing or a foamedthermoplastic backing. Preferably, the thermoplastic foamed backing is afoamed vinyl backing, and more preferably a polyvinyl chloride foamedbacking, such as a closed-cell vinyl foamed backing. Generally, thebackings will contain a sufficient amount of at least one blowing agentand plasticizer and can include other ingredients conventionally used inbackings.

Chemically expanded thermoplastic foamed backings can he used as thesecondary backing and can be prepared by casting a thermoplastic resinplastisol containing a blowing agent onto the back of the primarybacking and heating to expand and fuse the plastisol. Alternatively, apre-blown foamed secondary backing can be laminated, such as by heat, tothe primary backing. The solid thermoplastic secondary backing can besimilarly prepared by casting or by lamination.

Conventional blowing agents can he used and include, but are not limitedto azodicarbonamite, oxybissulfonyl hydroxide, substituted thiatriazole,and the like such as the ones described in U.S. Pat. No. 3,661,691incorporated its entirety by reference herein.

The recycled powder is obtained from post-consumer products bysubjecting the product, such as a vinyl backed product, to a processwhich reduces the post-consumer product into a number of pieces (e.g.,chunks or granules) which can eventually he further reduced in size toform a powder. One operation that can be used to reduce, for instance,the vinyl backed carpet or vinyl backed manufacturing waste, to asuitable recycled powder is to first subject the carpet or waste to aface shear operation to remove at least a portion, if not most of theface fiber that may he present. While this step is an optional step, itis preferred that at least a portion of the face fiber, and even morepreferably at least 50% of the face fiber, and even more preferably atleast 75% of the face fiber, be removed to improve the end use purity ofthe recycled material which eventually will be formed into a surfacecovering backing layer. While there are various types of devices whichcan remove the face fibers, like pure nylon fiber, which may be attachedto the vinyl backed carpet, one preferred device is a shearing machine,such as one commercially available from Sellers, Inc., United Kingdom.

Whether or not any face fiber is removed from the vinyl backed carpet orvinyl backed manufacturing waste, the carpet or waste is then fed into ashredder which breaks down the carpet and waste into various pieces,chunks, or granules. The particular size of the pieces is not critical,so long as the carpet or waste is somehow “cut up” or formed into piecesso that the carpet or waste can eventually and preferably be reduced topowder form. Preferably, these chunks or granules have a diameter ofabout 4″ or less, and more preferably have a diameter of about 3″ orless, and most preferably have a diameter of about 2″ or less.Preferably, the diameter range of these chunks or granules is from about1″ to about 2″. One device that can be used to reduce the carpet and/orwaste to such chunks or granules is a shredder, such as one commerciallyavailable from Nordfab, Inc., Model #1350K.

The chunks or granules are then reduced to a smaller size by subjectingthem to any operation which can accomplish this purpose. For example, agranulator can he used; for instance, one available from RapidGranulator, Model 3260 with a screen size of ¼ inch, which can reducethe chunks or granules to a size of about ½″ or less, more preferablyabout ⅜″ or less, and most preferably about ¼″ or less. Preferably, thechunks or granules are reduced to a size of from about ½″ to about ¼″,more preferably from about ⅜ to about ¼″. With the use of a granulatoror similar device, the size of the resulting chunks or granules can beadjusted to any desired size and thus it is certainly within the boundsof the present invention to vary the size of the particles to sizesdesired by the ultimate use of the recycled material.

The chunks or granules now reduced to a smaller size, are thenoptionally subjected to an operation which can separate substantiallyany existing fiber from the chunks or granules present. This fiber whichmay be present is generally face fibers and this operation preferablyremoves any low density fibers from the granules or chunks which aretypically of a high density. One method of separating at least a portionof the fibers from the granules or chunks at this stage, is an aspiratorusing an air stream separation design. One machine capable of doing thisseparation is a KF-60 extended aspirator available from Kongskilde. Inthis optional step, it may be desirable to have a portion of the fiberremain with the granules or chunks of the recycled material or it may bedesirable to remove almost all of the fiber, if not all of the fiber,depending upon the end use of the backing which will be formed from therecycled material.

The granules or chunks, which may have some fibers attached or present,are then preferably reduced in size to form a powder. Any means can beused to reduce the larger sized granules or chunks to a powder.Preferred ways of doing so is with the use of a grinder or cryogenicgrinding process. If very fine powder is required for the particular enduse, then a cryogenic grinding process is preferred which can beaccomplished by spraying the granules or chunks of recycled materialwith liquid nitrogen and then subjecting the sprayed recycled materialto a grinding process. The cryogenic process forms finer powder becauseof the brittleness of the material resulting from the liquid nitrogentreatment and because of the reduced agglomeration of the materialduring the grinding process. If the powder size is not as important,then an ambient grinding process can be used with any type of grindersuch as a Wedco Therm-O-Fine UR-28 grinding system available from Wedco,Inc. Any size of recycled material can he used in the backing orintermediate layer, so long as the material can take the form of abacking or intermediate layer by fusing, which will be described in moredetail below. It Is preferred that the recycled powder have a particlesize of 3,000 microns or less and more preferably 1,000 microns or less.A preferred range of powder size would be from about 250 microns toabout 1,500 microns, and a more preferred range would be from about 300microns to about 900 microns. FIG. 1 summarizes the preferred steps ofmaking the recycled powder.

The recycled powder upon analysis typically contains at least onethermoplastic material, such as a vinyl-based material, and can alsocontain at least one plasticizer, at least one inorganic filler, atleast one stabilizer, and generally a small amount of face fibers, suchas nylon, polypropylene, polyester, and/or glass fibers. These fiberswhich may he present can assist as acting like a reinforcement fibermaterial in the backing layer once the recycled powder is fused.

The recycled material, preferably in powder form, which is formed can beused alone to form a backing or intermediate layer or can be mixed withother conventional ingredients, such as virgin thermoplastic material toform the backing or intermediate layer. Any combination of the recycledmaterial with virgin material is possible. For instance, from about 1%by weight recycled material to about 100% recycled material can be usedalong with from about 0% virgin material to about 99% by weight virginmaterial to form a mixture which can ultimately be fused into a backinglayer or intermediate layer. Preferably, when forming the final backinglayer, a backing layer containing about 100% recycled material ispreferred. When an intermediate backing layer is formed, it is preferredthat at least 10% by weight virgin thermoplastic material is alsopresent with the recycled material, and more preferably at least about50% by weight virgin thermoplastic material is present along with therecycled material, and most preferably at least about 90% by weightvirgin thermoplastic material is present along with the recycledmaterial.

Besides virgin thermoplastic material, other conventional ingredientscan he present along with the recycled material to form a backing orintermediate layer, such as inorganic fillers, resins, plasticizers,stabilizers, foaming agents, blowing agents, and the like. The amount ofany one of these ingredients can be the same as conventionally used bythose skilled in the art in forming such layers. Since a foaming orblowing agent can be incorporated into the recycled material, a foamlayer or cushion-backed layer can be formed with the recycled materialof the present invention.

In forming the backing or intermediate layer, the recycled material,preferably powder, with or without additional ingredients or components,is applied onto a substrate in any manner in which powders can beapplied to eventually form a continuous layer, which is preferablysubstantially uniform in thickness. The substrate can be a releasepaper, a belt, or preferably, the bottom surface of a primary backing orother layer in a carpet or other surface covering. Once the recycledpowder with or without other ingredients or components is applied,preferably in a uniform or substantial uniform fashion, the recycledmaterial is fused to form a continuous layer. Fusing or fused, forpurposes of the present invention, is understood to mean that therecycled material, preferably a powder, is not completely reduced to aliquid state, like liquid plastisol, but instead, is the joining of theindividual particles or granules of the recycled material, in anymanner, preferably with the application of heat, to form a continuouslayer. Generally, some of the recycled particles or granules, andpreferably a majority, and most preferably over 90% of the recycledparticles or granules substantially maintain their identity as particleson a macroscopic level, but are part of the continuous layer. In oneembodiment of the present invention, after the recycled material hasbeen fused to form a continuous layer, visually, one can identify manyof the individual recycled particles in the backing layer. The fusing ofthe recycled material is preferably with the application of heat andpressure. More preferably, the fusing of the recycled material isaccomplished with the use of a double-belt press such as one availablefrom Schilling-Knobel of Germany.

With a double-belt press, the recycled material and any other layers ofthe surface covering travel between a moving top belt and a movingbottom belt where heat is applied through each belt onto the recycledmaterial. Generally, a heated platen is located above the top belt andbelow the bottom belt to provide the application of heat onto the beltand then onto the recycled material. This platen can also providepressure onto the recycled material. Preferably, the heated platenprovides up to about 100 psi and more preferably about 40 psi or less,and even more preferably about 0.1 psi to about 10 psi onto the recycledmaterial. Most preferably, no pressure is applied onto the recycledmaterial at this point. Preferably, any pressure that may be appliedthrough the platens is at a consistent pressure. The temperature appliedto the recycled material is generally a temperature sufficient to fusethe recycled particles of the recycled material together without causingany substantial melting of the recycled particles. The top belt ispreferably maintained at a temperature of from about 215° C. to about220° C. while the bottom belt which is the furthest away from therecycled material is preferably kept at a temperature of from about 110°C. to about 130° C. so as to avoid any damage to the other layers whichmay exist with the recycled material. Once the recycled material with orwithout other layers present is heated and fused, the material thenpreferably goes between two sets of nip rolls which apply a pressure ofabout 75 psi or less onto the material traveling on the belts and thenthe material goes through a cooling zone wherein cold water or othercooling medium is circulated through additional platens located abovethe top belt and below the bottom belt which cools the belt and coolsthe surface covering. Preferably, during the fusing stage, the pressureand temperature are held constant or substantially held constant. Thematerial then can he rolled if desired onto a roller or fed into acutter. FIG. 2 depicts a preferred process of making the surfacecovering with the use of a double belt press.

In a more preferred embodiment, a surface covering, in this case, a hardbacked carpet can be made as follows. Unbacked carpet is placed on anunwinding station where this unbacked carpet is fed face down on amoving belt preferably the bottom belt of a double-belt press. Theunbacked carpet can be a primary backing with textile fibers extendingupwardly from the backing and forming a surface. With the carpet facedown on the bottom belt of the double-belt press, an adhesive orpolymeric pre-coat is applied, for instance, by applying a dispersiongrade or suspension grade thermoplastic resin onto the primary backingor unbacked carpet. This adhesive or polymeric pre-coat layer can be a100% virgin dry blend or can be a mixture of virgin material along withrecycled material. In lieu of a dry blend, a liquid grade resin can beapplied as the adhesive or polymeric pre-coat layer. Preferably, a dryblend is applied. The adhesive or polymeric pre-coat layer is applied inconventional amounts, but preferably the amount is from about 15 ouncesper square yard to about 60 ounces per square yard. Preferably, theadhesive or polymeric pre-coat layer is a dry blend of at least one PVCresin, at least one plasticizer, and at least one stabilizer.

If the adhesive or polymeric pre-coat layer is a dry grade, the materialalong with the unbacked carpet is vibrated by a plate underneath thebottom belt which aids in the particles in the adhesive or polymericpre-coat layer to fall between the fiber bundles and improves thedispersion of the particles on the unbacked carpet. The material canthen he subjected to a process which will gel the adhesive or polymericpre-coat layer, such as with the use of infrared heat. Then, areinforcement material is applied onto the surface of the adhesive orpolymeric pre-coat layer. Examples of reinforcement materials include,but are not limited to, a non-woven material or woven material, such asa non-woven fiber glass mat or fleece and the like. This reinforcementmaterial is generally placed on the surface of the adhesive or polymericpre-coat layer while the layer is still in a liquid or gel state. Priorto or after the reinforcement material is applied, an intermediate layercan be applied.

The intermediate layer can be formed from 100% recycled material or cancontain lesser amounts of the recycled material or can contain 100%virgin material. Preferably, the intermediate layer contains at least50% virgin material and more preferably at least 75% virgin material andmost preferably at least 90% virgin material with the remaining balancebeing substantially recycled material. This intermediate backing layeris also an optional layer and can be made from the same material as thesecondary backing layer. Preferably, the intermediate backing layer is ahard backed and is not a foamed layer. The intermediate layer ispreferably a thermoplastic material and more preferably is a polymer orcopolymer of a vinyl compound, such as polyvinyl chloride. Theintermediate backing layer is preferably applied in the form of a dryblend but can be applied as a liquid coating. The intermediate backinglayer whether applied as a dry blend or as a liquid coating can beapplied in the manners conventionally known to those skilled in the art.Preferably, the amount of intermediate layer applied is an amount offrom about 10 oz/yd² to about 150 oz/yd².

Once the reinforcement material is applied, the carpet can then besubjected to a suitable pressure to create a good bond between theindividual fibers and/or yams the adhesive or polymeric or pre-coatlayer as well as the reinforcement material with the pre-coat layer. Anapplication of pressure of this sort can be applied by a pressure rolleror other suitable device.

The unbacked carpet can then move to a station where the final backingis applied which preferably is from a 100% recycled powder. Thismaterial can he applied with the use of a scattering machine or otherconventional application device just like the dry adhesive or polymericpre-coat layer. Preferably, the recycled material powder is applied inan amount of from about 40 to about 150 ounces per square yard, and morepreferably from about 70 to about 90 ounces per square yard, and mostpreferably about 80 ounces per square yard. As described above, thematerial, once substantially uniformly applied to the unbacked carpet,is then subjected to a fusing process. The carpet can then he subjectedto a cooling zone also described previously and then rolled or fed to acutter.

Referring to FIG. 2, an unwinding roll (50) contains release paper orthe primary backing of a carpet or other layer which is unwound onto thelower belt (51) of the double belt system (53). A scattering machine(54) scatters powder containing the pre-coat ingredients which cancontain recycled powder onto the material being unwound from (50), andthe vibrating chute assists in evenly distributing the powder uniformlythroughout the layer on the bottom belt. An infrared heater (54) is usedto heat pre-coat material to gel or fuse the pre-coat material, and thenfiberglass is applied to form a reinforcement layer and a crush roll(55) is used to crush the fiberglass onto the pre-coat layer.Afterwards, a scattering/cooling machine (56) is used to applied thesecondary backing layer material which contains at least the recycledpowder. Then, a second infrared unit (57) is used to heat the secondarybacking material. A series of heating platens (58) is located above theupper belt (60) and below the bottom belt (51) and the heater (59) isused to heat the platens (58). Nip rolls (61) are used to press thematerial on the belt. Cooling platens (62) are then used above the upperbelt (60) and below the bottom belt (51) to cool the material. Finally,a belt cleaning system (63) is used to remove debris from the belts anda rewinding roll (64) is used to roll the finished product.

FIGS. 3 a) through e) depict various embodiments of the preferredsurface covering which is a textile product. In each embodiment in theFigure, fibers (65) are located on top and a secondary backing (70) islocated at the very bottom of the covering and a primary backing layer(66) secures the fibers (65). A reinforcement layer (68) can be locatedbeneath the pre-coat layer (67) and/or beneath an intermediate layer(71). An intermediate layer (69) can also be located beneath thereinforcement layer (68). In each case, each layer is affixed in somemanner such as by casting, adhesive, or other means conventional in theart.

As an alternative to using the primary backing as the substrate in whichall other layers are applied thereto, it is certainly within the boundsof the present invention to make any layer of the surface covering firstand then add other desirable layers to the top and/or bottom surface ofthe first layer made. For instance, the secondary or final backing layercan be made first and then all layers applied thereto.

Besides the above embodiment relating to the use of recycled material inone or more layers of a surface covering, another aspect of the presentinvention is a surface covering wherein the secondary backing layer andpreferably the adhesive or polymeric pre-coat layer are made from drypowder blends instead of liquid blends. The advantage with such a systemwould be that the powder blends are less expensive and are easier tohandle in the manufacturing process. In such a process, the layers canbe formed in the same manner described above with respect to theformation of a layer using recycled material such that the virginmaterial forming the secondary backing, or other layer will form acontinuous layer by fusing or be subjected to sufficient heat to meltthe powder to form a continuous layer. The use of the double-belt pressdescribed above would be preferred in forming a surface coveringcontaining one or more layers from a dry powder blend. Preferably, thesecondary backing would contain a dry blend of a polymeric resin such aspolyvinyl chloride along with other optional conventional ingredients ina dry blend form, such as at least one plasticizer, at least one filler,at least one stabilizer, and the like. A foaming agent in the form of adry blend can also be included. An intermediate backing layer and/or anadhesive or polymeric pre-coat layer can be formed in the same fashionas described earlier. It is within the bounds of the present inventionto first form one layer and subject the dry powder blend in the shape ofa layer to appropriate heat to form a continuous layer and then add asecond layer in powder form to the top or bottom surface of the firstformed continuous layer and so on. Alternatively, the layers can all heformed on top of each other in powder form and then subjected at onetime to sufficient heat to form a continuous multi-layered surfacecovering.

Whether a surface covering contains recycled material or 100% virginmaterial, the process of curing all at one time is particularlypreferred in making resilient vinyl flooring where all layers are firstformed and then the entire surface covering is subjected to sufficientheat to form a multi-layered resilient vinyl flooring which can thenhave optional strengthening layers, wear layers and/or top coat layersapplied afterwards, such as in the manner described in U.S. Pat. No.5,458,953 incorporated in its entirety by reference herein.

In combination with the other embodiments of the present invention or asa separate alternative, the recycled material of the present inventioncan be added to the adhesive and/or pre-coat layer. In this embodiment,the adhesive and/or pre-coat layer are preferably applied as a liquidand the recycled material is added to the liquid in any fashion, such asby mixing with the liquid before the liquid is applied as a coat or therecycled material can be applied by introducing the recycled material ontop of the liquid once the liquid is applied as a coat (e.g., applyingthe recycled material on top of the liquid coat by scatteringtechniques). Any amount of recycled material can be applied in thisfashion, and preferably the amount is from about 1% by weight of theliquid coat to about 50% by weight, and more preferably, from about 5%to about 15% by weight of the liquid coat. Similarly, any intermediatelayer or even the backing layer, such as the ones described above, canhave recycled material introduced and present in the same manner (i.e.,recycled material added to liquids which form the layer) as a separatealternative; meaning, the backing layer need not contain recycledmaterial as long as some other layer(s) contains recycled material. Morethan one layer can contain recycled material and preferably, the entiresurface covering has from about 1% by weight to about 20% by weightrecycled material.

The present invention will he further clarified by the followingexamples, which are intended to be purely exemplary of the presentinvention.

EXAMPLES Example 1

A surface covering, such as a final hard backed carpet was made in thefollowing manner. A carpet was made in the same manner as describedabove with respect to the preferred embodiment of using an adhesive orpolymeric pre-coat layer having the formula A described below in Table 1and the use of a fiberglass fleece (1.0 lb-2.0 lb/100 ft², e.g. 1.4lb/100 ft²) obtained from Johns Manville. The unbacked carpet used was a26 ounce loop obtained from Mannington Carpets- 1/10 gauge. The final orsecondary back coat was applied in powder form as shown in FIG. 2 usingthe preferred amounts and parameters described above in the preferredembodiment.

The final back coat was formula R. Formula R is recycled powderresulting from vinyl back carpet tile and carpet waste which wassubjected to a face shear operation to remove substantially all of thefiber with a Sellers Shearing Machine. The sheared carpet tile andcarpet waste were then fed into a Nordfab 1350K shredder to form 2″ orless granules or chunks which were then reduced to a smaller size of ¼″or less with the use of a Rapid Granulator 3260. Low density fiber wasseparated out of the material with a Kongskilde KF-60 aspirator and thematerial was reduced to a powder having a size of from about 330 micronsto about 850 microns. Table 2 below, sets forth the various parametersused in making the carpet which was constructed on a double-belt pressobtained from Shilling-Knobel of Germany.

TABLE 1 Formulations Chemical Type Chemical PHR Co-Polymer Pre-CoatFormulation-(A-Powder) PVC Resin VC-113 100 Flame Retardant AluminumTrihydrate 120 Plasticizers Blend S-160 (60% by wt.) 22.5 DINP (40%)Stabilizer Tile 1.5 Stearic Acid 1.0 Homo-Polymer PVCBack-Coat-(B-Powder) PVC Resin VC 57 100 Filler CaCO₃ 180 PlasticizerBlend S-160 (60% by wt.) 60 DINP (40%) Stabilizer Tile 1.5 Stearic Acid1.0 Foam Backing Dry Blend Formulation-(F-Powder) PVC Resin Geon 438 100Flame Retardant Aluminum Trihydrate 60 Filler CaCO₃ 60 Plasticizer BlendS-160 (60% by wt.) 70 DINP (40%) Stabilizer Tile 2.0 Foaming AgentAZ-120 2.4 Activator Kadox 920 1.0

TABLE 2 Precoat Back Coat Carpet Precoat Weight Fiberglass Back CoatWeight Top Belt Bottom Belt Belt Speed Belt Gap Infrared ConstructionType gms/m² fleece Type gms/m² Heat Heat m/min mm Both @ 26 oz LoopA-Powder 818 Yes Recycled 2724 215° C. 130° C. 2 8 50% Granules 26 ozLoop A-Powder 818 Yes Recycled 2724 215° C. 130° C. 2 8 70% Granules 26oz Loop A-Powder 818 Yes Recycled 2724 215° C. 130° C. 2 8 60% Granules26 oz Loop A-Powder 818 Yes Recycled 1090 2l5, 205,  90° C. 2 8.5/10 PC60% Granules 195° C. BC 50%

Example 2

A vinyl floor covering was made using the process of the presentinvention. In particular, on a belt, recycled material having Formula Rwas applied in an amount to create a 40 mil thick layer which on top wasapplied PVC pellets to form a second layer of 40 mils in thickness. Bothlayers, in powdered form, were then fused to form a continuousmulti-layer product. A top coat containing an UV curable urethane-basedacrylate thermoset from Lord Corporation was then applied in the mannerdescribed in U.S. Pat. No. 5,405,674, incorporated in its entirety byreference herein, to form the final product.

Example 3

A surface covering containing layers made from powder blends was madefrom using the double-belt press and procedure in Example 1. The processsteps of Example 1 were followed except that in lieu of Formula R as thefinal backing layer, Formula B or Formula F were used to form the finalbacking layer.

Table 3 below sets forth some results from surface coverings made fromExamples 1 and 3.

TABLE 3 Example 1A 3A 3B 1B Radiant Panel (ASTM E-648) .70 — .78 .56 NBSSmoke FL (ASTM E-662) 474 444 515 435 Tuft Bind Dry (ASTM D-1335) 7.89.9 2.5 6.6 Tuft Bind Wet (ASTM D-1335) 6.4 7.4 1.5 5.4 Delamination(ASTM D-3936) No No No — Flatness (ITTL Test-5 means carpet 4 — 2-3 4totally “hugs” the floor)

Other embodiments of the present invention will he apparent to thoseskilled in the art from consideration of the specification and practiceof the present invention disclosed herein. It is intended that thespecification and examples be considered as exemplary only, with a truescope and spirit of the present invention being indicated by thefollowing claims.

1. A method of making a backing for a surface covering comprisingobtaining recycled particles from a recycled carpet material by aprocess consisting of optional shearing, shredding, granulating,optionally elutriating, and grinding, and applying said recycledmaterial in the form of particles on a substrate to form a layer,wherein said recycled material comprises a thermoplastic material; andfusing said recycled particles to form a continuous backing layer. 2.The method of claim 1, wherein said fusing is achieved with theapplication of heat and optionally pressure.
 3. The method of claim 1,wherein said fusing occurs in a double-belt press.
 4. The method ofclaim 3, wherein the double-belt press comprises a bottom belt and a topbelt, wherein said bottom belt is kept at a temperature from betweenabout 110° to about 130° C. and said top belt is maintained at atemperature of from about 215° to about 220° C.
 5. The method of claim1, further comprising applying virgin thermoplastic material along withsaid recycled material to form a layer.
 6. The method of claim 1,wherein said recycled particles after fusing substantially maintaintheir identity as particles on a microscopic level.
 7. A method forpreparing a backing for a surface covering comprising reducing vinylbacked carpet, vinyl backed carpet manufacturing waste, or both intogranules and fibers; separating at least a portion of the fibers fromthe granules; reducing said granules to a smaller particle size to forma powder; applying the powder to a substrate to form a layer andpressing said powder; fusing said powder for a sufficient time andtemperature in form a continuous backing.
 8. The method of claim 7,wherein prior to reducing the vinyl backed carpet, vinyl backed carpetmanufacturing waste, or both to granules, said process further comprisesremoving at least a portion of any face fiber from said vinyl backedcarpet.
 9. The method of claim 7, wherein said granules have a size offrom about ¼″ to about 3/16″.
 10. The method of claim 7, wherein saidgranules are formed by subjecting the vinyl backed carpet, vinyl backedmanufacturing waste, or both to a shredder.
 11. The method of claim 10,wherein said shredder reduces the vinyl backed carpet or the vinylbacked manufacturing waste to granules having sizes of from about 1″ toabout 2″ wide.
 12. The method of claim 7, wherein at least a portion ofsaid fibers are separated from the granules using an aspirator with airstream separation.
 13. The method of claim 7, wherein said granules arereduced to a powder by an ambient grinding process or a cryogenicgrinding process.
 14. The method of claim 7, wherein said substrate ispositioned so that said substrate is a bottom surface of a primarybacking, with textile fibers extending upwardly from the primary backingand forming a surface.
 15. The method of claim 7, further comprisingfeeding a roll of primary backing onto a belt prior to applying thepowder, applying dispersion grade or suspension grade thermoplasticresins onto the back of the primary backing to form an adhesive orpolymeric pre-coat layer; vibrating the primary backing; reducing theadhesive or polymeric pre-coat layer to a soft gel; placing areinforcement material on the bottom surface of the adhesive orpolymeric pre-coat layer and applying pressure, and wherein the powderis applied onto the bottom surface of the reinforcement material. 16.The method of claim 7, wherein said continuous backing is passed throughcooling zone.
 17. The method of claim 7, wherein said fusing occurs on adouble-belt press.
 18. A method of making a surface covering comprisingforming an adhesive or polymeric pre-coat layer onto a primary backingby fusing or melting particles comprising a first thermoplasticmaterial; forming a secondary backing layer on said adhesive orpolymeric pre-coat layer by fusing or melting particles comprising asecond thermoplastic material, wherein said first and secondthermoplastic material are the same or different.
 19. The method ofclaim 18, wherein said first thermoplastic material and said secondthermoplastic material comprises polyvinyl chloride particles.
 20. Themethod of claim 18, wherein prior to forming the secondary backinglayer, a reinforcement material is placed in between the adhesive orpolymeric pre-coat layer and the secondary backing layer.
 21. The methodof claim 18, further comprising applying an intermediate layer ofparticles comprising a thermoplastic material after applying theadhesive or pre-coat layer, and then placing a reinforcement materialonto the formed intermediate layer prior to the formation of thesecondary backing layer.
 22. A method of making a vinyl floor surfacecovering comprising forming a substrate from recycled thermoplasticparticles; and applying on a surface of the substrate a wear layercomprising vinyl-based particles; and subjecting the two layers tosufficient heat and optionally pressure to form continuous layers whichare adhered to one another.